A number of benzo(b)thiophenes and 1-methylindole analogs of 5,6-dihydroxytriptamine will be synthesized, and their effects on release of serotonin and norepinephine in the brain will be investigated. 5,6-Dihydroxytryptamine has been shown to produce a long-lasting depletion of serotonin in the brain, but the sulfur analog leaves serotonin levels unchanged while causing depletion of norepinephine levels. It is hoped that a study of various analogs, such as the 5-hydroxy-6-methoxy, 5-methoxy-6-hydroxy, and 5,6-isopropylidenedioxytryptamine, and some of its bioisosteres, may shed light on the different biological mechanisms involved. The sulfur analog of melatonin, 5-methoxy-3-Beta-acetamidoethylbenzo(b) thiophene, will be studied for its intermediary metabolic products. This study will necessitate synthesizing some of the possible metabolites for GC-MS characterization. Further, certain position isomers and homologs of melatonin will be prepared for comparison of biological activities, and these compounds cyclized to produce position isomers and homologs of harmaline, the sulfur analog of which has been shown to have a high degree of monoamine oxidase inhibition. (Bosin, et al, Life Sciences 11, 685 (1972). BIBLIOGRAPHIC REFERENCES: Comparative Toxicological Studies of Indole, Benzo(b)thiophene, and 1-Methylindole Derivatives. T.R. Bosin, E. Campaigne, A Dinner, R.B. Rogersand, R.P. Maickel, Jour. Toxicology and Environmental Health, 1, 515-520 (1976). Hydroquinone and Quinone Derivatives of the (Z)-and (E)-Beta-Thiocrotonates, E. Campaigne and Yasuo Abe, Bull. Chem. Soc. Japan, 49, 559-562 (1976).